Resizing Pictures for Prints...?

Okay. My aunt took my senior pictures, and I put the name and the date on by myself. The only problem is that Sam's Club cropped the images to make them into wallets, effectively cutting off most if not all of the name and date. How should I fix this? Crop the image myself, if so, to what dimensions?
If I should resize the image, how would I go about that? And what is a good dpi for images like that? Thanks...